74 Rev. J. Barlow on the application [March 30, 



artificial heat, are less prone to decompose, even though they be not 

 isolated from atmospheric air and moisture. Hay and dried fruits 

 are obvious examples of the application of this principle. 



B. Principle of isolation from atmospheric influences^ the albu- 

 minous constituent remaining uncoagulated. 



An expedient for protecting meat on this principle has recently 

 been carried out on a large scale at Paris. It is described at 

 length in the AssemhUe Nationale of the 23rd of January (quoted 

 in the Siecle of the 22nd of February). The flesh is immersed in 

 a gelatinous solution, which, when dry, forms an air-tight integument. 

 It is named by the inventor " vernis cristallise," and is said to 

 make an excellent soup. — Joints of meat, both raw and fresh, and 

 eggs, which had been prepared five months before by this process, 

 were exhibited by Mr. M. Rennie : all appeared in good condition.* 



If meat be coated with dry wheaten flour, the time that it will 

 continue sweet may be prolonged threefold in tropical climates. 

 The flour probably acts as an isolator against air and moisture. 



The preservation of organic substances in glycerine, oil, and 

 syrup, and the more familiar process of salting,! probably derive 

 their efficacy from the principle of isolation. J 



But, although brine effectually protects the meat which it sur- 

 rounds against atmospheric oxygen, " flesh by salting loses in point 

 of nutritive value, in consequence of the removal and division of the 

 salts indispensable to sanguification. "§ This was illustrated by 

 experiments on brine, which was obtained from a piece of beef salted 

 in the course of the day, and proved to contain albumen, phosphoric 

 acid, lime, and iron. 



The following preparations made with glycerine, were exhibited — 



(a) A small piece of flesh which had been partially immersed 



since February 20, 1855, in a bottle containing a small quantity 



of glycerine. By daily agitating this bottle, that part of the flesh 



which rose above the surface of the fluid was kept moist. 



{b) In each of two jars of glycerine about 4 lbs. of meat were 



* The specimen of raw flesh thus prepared had shrunk, as if the " vernis 

 cristallise " had acted as the skin of a grape when it becomes a raisin ; i.e. it 

 had permitted the escape of constituent moisture, but had prevented the 

 admission of atmospheric moisture. 



t On April 23rd, 1841, Mr. Macilwain gave an evening discourse on 

 Payne's mode of salting, by subjecting the substance to atmospheric pressure. — 

 Literary Gazette, for 1841, p. 280. Repertory of Patent Inventions, Vol. xvii. 

 p. 168.' 



X It was shown, by placing vessels of glycerine and strong brine under the 

 exhausted receiver, that the latter is almost entirely, the former absolutely, 

 free from dissolved air. 



§ Liebig's " Familiar Letters," p. 430. 3rd Ed. 



II It has been suggested, that the sensation of thirst, experienced after eating 

 salt meat, may, in some degree, be owing to the tendency of a saline solution 

 to dry up animal membranes. 



